html,
body,
#root {
  height: 100%;
}
.App,
.app-box {
  height: 100%;
}

.blue {
  background: blue;
}
.pannel-left {
  position: relative;
}
.bottom-btns {
  position: absolute;
  width: 100%;
  left: 0;
  bottom: 0;
}

.empty-tip {
  margin-top: 80px;
  font-size: 30px;
  text-align: center;
  color: lightgray;
}
.icon-btn {
  border: none;
  background: inherit;
}
